Transfer sheets, such as typing correction paper, carbon paper, decalcomania sheets and the like, typically comprise a thin opaque coating layer on a carrier sheet, such as fabric, paper or a deformable plastic sheet like polyethylene. The coating layer is subject to transfer to another surface by the application of a certain pressure level, such as the pressure exerted by a typewriter key, but is immune to transfer by light pressure, such as by ordinary handling or use. In effect, such transfer sheets permit the physical movement of a portion of the dry coating layer to another surface on the application of pressure which is sufficient to rupture the adhesive bond of the coating layer to the carrier sheet, and which increases the adhesive bond in the dry coating layer. Depending on the particular use, the coating layer may be the same or a different color or shade than the surface to which the layer is to be transferred. In correction paper, the coating layer more commonly is designed to match the paper to be corrected so that erroneously typed characters may be effectively masked by the use of the correction paper.
Pressure-sensitive transfer sheets, particularly correction paper as presently commercially marketed, typically comprise a carrier sheet with a coating composition composed of a pigment like titanium dioxide to provide opacity, a transferable binder composed of metallic soaps, waxes, resin and/or oils, and an adhesive agent to affix or adhere the binder and pigment lightly to the carrier sheet prior to cohesion and transfer of the coating layer on the application of pressure. Typical transfer sheet materials and the coating compositions employed are described in U.S. Pat. Nos. 2,931,752; 3,025,180; 3,515,572; 3,552,990; and 3,776,756. Our invention relates to the field of transfer sheets and improved transfer sheets, particularly typing correction papers and to methods of preparing such materials.